Sulawesi babirusa  (Babyrousa celebensis)

The Sulawesi babirusa is classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix I of CITES (3).

With the male’s curling tusks, this is one of the world’s most bizarre looking mammals. Indeed, so bizarre is this animal’s appearance that it has inspired some Indonesian people to make demonic masks based on them and even offer the animals themselves as gifts to visitors (4). The name babirusa means ‘pig-deer’ and refers to its appearance as a mix between a pig and a deer (2). Babirusas are in fact members of the pig family, and there are currently three species of babirusa recognised (1). The Sulawesi babirusa is the largest of the three species (2) and also the least hairy, with just a sparse covering of barely discernable hairs on its rough, brownish-grey skin (2) (5). The remarkable tusks of the male are actually the babirusa’s upper canines, which penetrate through the skin of the nose and then curve over the face towards the forehead. The sharp-tipped lower canines also protrude out from the jaw (4). The canines of the smaller female Sulawesi babirusa are either absent, or very much reduced (2). Although the function of these peculiar tusks is not clear, their brittle, easily breakable nature means they are rarely used in combat (2).

This species inhabits the peculiarly-shaped Indonesian island of Sulawesi; however, as the taxonomy of babirusas remains uncertain, so does their exact range (1). The Sulawesi babirusa is definitely known to inhabit the northern peninsula and the north-eastern part of Sulawesi, and its range may also encompass central, eastern and south-eastern Sulawesi, although further studies on this animal’s taxonomy are required before this can be confirmed (1).

The Sulawesi babirusa is typically found along the banks of rivers and lakes, in tropical rainforest where there is abundance of aquatic plants. Once the Sulawesi babirusa favoured low-lying areas, but today it is found more frequently on higher and less accessible ground, further from the activities that threaten it (1) (2).

This enigmatic mammal has a varied diet of leaves, roots and fruits (2), which are uncovered by probing the wet muddy ground or soft sand (1), as well as small mammals, which are caught and consumed by adult babirusas (2). The Sulawesi babirusa has remarkably strong jaws and teeth to be able to deal with this array of food, and it can reportedly crack hard nuts with ease (2). On the island of Sulawesi, deposits of salt can be found near hot springs and volcanic vents. The Sulawesi babirusa visits these salt licks where it spends time chewing on rocks, ingesting soil, and drinking water from the hot spring (6). Such peculiar behaviour is likely to be a way of the babirusa obtaining sufficient sodium, although the salt lick also acts as a venue for many social activities, such as courtship and combat (6).

The Sulawesi babirusa is a rather social animal, thought to live in groups of up to eight individuals, and is active during daylight hours. As well as around salt licks, the babirusa can be seen congregating around water and wallows (2). It bites off branches of leaves under which to shelter from the rain (2), and there are reports that the babirusa also constructs nests in which to sleep (5), although it has also been said that they sleep in simple depressions in the ground (2).

To give birth, females construct a rather defined nest; measuring up to three metres long and 25 centimetres deep, this nest is formed from branches torn from trees and bushes (2). A litter of normally one or two young are born after a gestation of 155 to 158 days. In captivity, female Sulawesi babirusas have given birth to young at all times of the year, although in the wild, due to differences in diet and environment, females are likely to reproduce much les frequently (2). Captive individuals have also indicated that young become sexually mature at five to ten months of age, and that an individual may live for up to 24 years (2).

The Sulawesi babirusa is now considered to be Vulnerable to extinction (1), a status brought about by a long history of hunting by humans, combined with more recent large-scale commercial logging operations (2). Babirusas are one of the first animals to disappear when the rainforest is disrupted for logging, and the roads that are cut into previously inaccessible forest to initiate logging operations result in the babirusa being more exposed to hunters with their nets, spears and dogs (2). Lowland forest on the island of Sulawesi, once the preferred habitat for this babirusa, has now been reduced to less than 25 percent of its original cover (1), highlighting the need for the remaining forest to be conserved.

The Sulawesi babirusa may be fully protected under Indonesian law and occur in several protected areas, but neither of these measures are effective enough to prevent this remarkable animal from being edged into its threatened existence (1). Large numbers of the Sulawesi babirusa can be found in zoos around the world, where breeding programmes are in place (1), but this captive population is said to be extremely inbred (2).

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn about conservation efforts in Sulawesi visit:

• Wildlife Conservation Society, Indonesia Program:
  www.wcsip.org/sulawesi